3.5. Animal studies
The wound healing performance of various samples on mice model
was observed at different time intervals (0, 4, 8 and 16 d) shown in
Fig. 11. The reduction in wound area was calculated and shown in Fig.
12. At the same day, no visible difference in wound appearancewas observed
for all groups. At the 8th d post-surgery, granulation tissue formation
was clearly observed in gel/nSnH, gel/nSnH/Aloe, gel/nSnH/
Cur and gel/nSnH/Aloe/Cur groups. The wound treatment with control
fabric showed only 60% wound reduction after 16 d while gel/nSnH
coated dressing showed 75% wound healing. While in other groups,
wound reduction is much faster in comparision to control and gel/
nSnH treated wounds. Silver has been speculated to reduce the time
for fibroblasts to invade wound tissue, it also appears to have good
anti-inflammatory properties which may increase re-epithelialisation
rates. The silver nanoparticles which are released from the matrix
slowly change to Ag+ under physiological conditions and interact
with bacterial cells present at the wound site. The Ag+ concentration
obtained from the sustained release is well within the safety limits
and thus, damage to normal human cells is avoided.
The high wound closure rate of gel/nSnH/Aloe than control and gel/
nSnH treated groups was due to synergistic effect of A. vera and nSnH
that were used in preparation of dressing material. After 16 d, the gel/
nSnH/Aloe treated wound healed 100% while gel/nSnH treated wounds
healed 75%. A. vera provide the moist environment to wound surface
and increased the collagen content of the wound due to this, it accelerated
thewound contraction and the rate of healing. One explanation for
this was that keratinocytes migrated more easily over a moist wound
surface than underneath scab [15]. This is the reasonwhywound reduction
of the gel/nSnH/Aloe treated wound was higher than that of without
A. vera on the 16th d.
While in case of gel/nSnH/Cur and gel/nSnH/Aloe/Cur dressings, the
wound healing phenomena is entirely different in comparision to the
above stated groups. The wound reduction area was observed 80% and
95% in case of gel/nSnH/Cur and gel/nSnH/Aloe/Cur dressing, respectively.
No scab and argyria were observed for the wounds treated with
other groups accept control dressings. In the case of control, fabric adhered
to the wound causing damage each time it was replaced. By
gross examination of the wound sites, it may also be inferred that scar
formation is minimum when wounds were treated with gel/nSnH/
Aloe based composite dressings.
3.6